A post by Whiteman in recommedations: Bundarra NSW...

"Indeed the whole of Thunderbolts Way proved worthwhile, just be careful coming down the BIG HILL between Nowendoc & Gloucester....10 & 15 degree slopes and only one run off area.....1st Gear Low Range these days is ok for me and yet still need to use some foot brake....ohh should mention it`s about 6k long..up or down !!"

This prompted me to remember: 

When  I was getting the lift by the towtruck we were discussing driving methods going down the highway near Toowoomba.   He mentioned going down wasn't so bad, but he had had a lot of tows going up.  Especially in peak hour.  All the stopping and starting caused clutch burnouts. Had not considered that.